摘要 |
The isolation and characterization of a novel polypeptide, designated Protease X, identified while screening for proteases exported into the media by Streptomyces lividans, is described [SEQ ID NO: 2]. Also disclosed is the DNA sequence of the gene encoding this protein [SEQ ID NO: 1]. The polypeptide was found to have proteolytic activity on the substrate succinyl-ala-ala-pro-phe-pNitroanilide, also cleaved by chymotrypsin, subtilisin, and cathepsin G. In addition, methods for purifying the protease and raising antibodies against it are reported. Lastly, the generation of an S. lividans strain deficient in this proteolytic activity is reported. Such a strain may prove useful as a host for production of heterologous protein products. |